 public class Example4_10 { 

   public static void main(String args[]) {

       Lader.下底=100;     //Lader的字节码被加载到内存,通过类名操作类变量

       Lader laderOne=new Lader();

       Lader laderTwo=new Lader();

       laderOne.设置上底(28);

       laderTwo.设置上底(66);

       System.out.println("laderOne的上底:"+laderOne.获取上底());

       System.out.println("laderOne的下底:"+laderOne.获取下底());

       System.out.println("laderTwo的上底:"+laderTwo.获取上底());

       System.out.println("laderTwo的下底:"+laderTwo.获取下底());

    } 

}
